44 results about "Active cancellation" patented technology

A multi-fan apparatus and method incorporates mutual active cancellation of fan noise and / or vibrations. The multi-fan apparatus includes two or more fans circuits, each comprising a fan, a fan speed controller and a separate tachometer, and a fan phase controller. The phase controller is connected to at least one fan speed controller and to each tachometer. Each fan's speed is independently and dynamically maintained at the same set speed by the fan speed controllers using an independent control loops. A noise and / or vibration cancellation phase difference between fans is determined in order to achieve destructive interference of pressure waves and, thus, noise and / or vibration reduction, in pre-determined region of a system incorporating the multi-fan apparatus. The phase controller establishes and maintains this cancellation phase difference between the fans based upon feedback from the tachometers.

A radio frequency receiver subject to a large in-band interferor employs active cancellation with coarse and at least one cancellation signals, each with a respective radio frequency combiner, in order to increase the effective dynamic range of the receiver for weak signals of interest. One or both can be digitally synthesized. This is particularly applicable for co-site interference, whereby the interfering transmit signal is directly accessible. A similar system and method may also be applied to external interferors such as those produced by deliberate or unintentional jamming signals, or by strong multipath signals. An adaptive algorithm may be used for dynamic delay and gain matching. In a preferred embodiment, a hybrid technology hybrid temperature system incorporates both superconducting and semiconducting components to achieve enhanced broadband performance.

A intelligent backhaul radio is disclosed, which can operate by zero division duplexing for use in PTP or PMP topologies, providing for significant spectrum usage benefits among other benefits. Specific system architectures and structures to enable active cancellation of multiple transmit signals at multiple receivers within a MIMO radio are disclosed. Further disclosed aspects include the adaptive optimization of cancellation parameters or coefficients.

An apparatus and method for active cancellation of interference at a hearing assistive devices are presented. The apparatus includes an interference cancellation circuit for cancelling an interference component of a composite signal, and an activator circuit for enabling interference cancellation circuit. The interference cancellation circuit generates an estimated replica of the interference from an interference profile, inverts the replica to form a cancellation waveform, then adds the cancellation waveform to the composite signal to cancel the interference component. An interference profile can be provided by performing a training sequence on a composite signal to detect a repetitive signal and building a profile using its parameters, retrieving a profile stored in memory, or using an antenna to capture an RF signal. The activator circuit may enable the interference cancellation circuit when RF energy is detected, when composite signal characteristics match one or more stored profiles, or in response to user input.

An engine mount structure is provided with active vibration mechanisms which are attached in the vicinity of the engine mount to prevent engine vibrations from propagating into the engine mounting structure, for example, the wing or fuselage structure of an aircraft. Additionally, sensors are provided on the engine and / or wing / fuselage structure to provide control signals to the active vibration mechanisms so that the active vibration mechanism react to the sensed data to minimize the vibration transmissibility from the engine into the wing / fuselage.

An active cancellation unit is disclosed for improving the noise cancellation between a transmitter and a receiver which are connected to an antenna using a duplexer, the unit comprising a coupler sampling a signal to transmit provided by the transmitter, a cancellation duplexer having characteristics similar to the duplexer and receiving the sampled signal to provide a simulated signal and an active component receiving the simulated signal and providing an amplified signal having a phase 180 degree shifted with respect to the simulated signal; and a coupler for injecting the simulated signal at the receiver.

Reducing, suppressing or canceling series parasitic inductance and / or resistive effects that affect the frequency response of components, elements and / or circuits in an electronic circuit or system that exhibit capacitance is disclosed. Noise generated by series parasitic inductance and / or parasitic resistance of the components, the physical orientation of the components, and / or the layout of components, devices and / or conductive tracks (board traces) on printed circuit boards within an electronic circuit or system is reduced, suppressed or canceled. The reduction, suppression or cancellation is achieved by adding a voltage source in series with a part or component of the electronic circuit or system that exhibits capacitance, the current source being adapted to deliver a compensating voltage of roughly equal magnitude and roughly opposite phase to parasitic voltage associated with the part or component.

An active cancellation system may be utilized to cancel interference, such as from transmitter leakage or self-interference in a transceiver of an electron paramagnetic resonance (EPR) spectrometer. The active cancellation system may be inserted between the transmitter and receiver. The active cancellation system may receive the output of the transmitter, and generate a cancellation signal with the same amplitude, but phase shifted relative to the self-interference signal. The cancellation system may include an attenuator / amplitude tuner, buffer, VQ generator, and phase shifter.